There's a particular issue with Labour because they used to be, at least in theory, a party run by the working class for the benefit of the working class. That's been eroding over many decades, and by this point they're basically the new Whig Party, full of patrician moralists who want to improve the working class.
A huge part of this is the whole Blairite constitutional settlement that's starting to look exhausted by now. We can put together key changes post 1997: legal reforms like the HRA and expansion of judicial review; devolution; turning the House of Lords into a House of Appointees; massively expanding the quango state, etc.
Many of those reforms, maybe all of them, could be defended on their own merits, but one effect of the whole package was to expand the size of, and change the composition of, the governing class. Keir Starmer is a really obvious product of this legalistic administrative state, he's done very well out of it, and now he's running it. It's no wonder he seems to find democracy an annoying nuisance.
And this all might be forgivable if it meant good government, but it doesn't. The quality seems to keep going down.
I know there's a strong tendency on FWR to use "populism" as a boo-word and say that protest votes are a bad thing, but it might be more productive to ask if voters' lack of trust in government is not due to manipulation by Russia/Israel/hedge fund bros, but just because our political class is not very capable.
It's not even as if Reform voters are very radical. They're basically normie Brits who are browned off with the state of the country. Your average Reform activist, in my observation, would be happy with a government that did the things Boris Johnson promised in 2019 but either didn't get around to (levelling up) or did the opposite (immigration).
There's even, you may not believe this but polling shows it, a chunk of floating voters wobbling between Reform and Greens. They're people who aren't political obsessives and don't think much about the ideological differences between those parties, vibes based voters if you like, they just know that they're outsiders and not Labour or Tory.